the degree of similarity in faunistic planktonic rotifer

Teka Kom. Ochr. Kszt. Środ. Przyr. – OL PAN, 2016, 13, 5–16
THE DEGREE OF SIMILARITY IN FAUNISTIC PLANKTONIC
ROTIFER ASSEMBLAGES IN THREE LAKES
LINKED BY WIEPRZ-KRZNA CANAL (EASTERN POLAND)
Andrzej Demetraki-Paleolog*, Marcin Kolejko**, Joanna Sender**
*
Department of Hydrobiology, University of Life Sciences in Lublin, Dobrzańskiego str. 37, 20-262 Lublin,
e-mail: [email protected]
**
Department of Landscape Ecology and Nature Conservation, University of Life Sciences in Lublin,
Dobrzańskiego str. 37, 20-262 Lublin, e-mail: [email protected]
Abstract. Dratów, Krzczeń and Tomaszne lakes are among environmentally valuable reservoirs in
Poland and Łęczyńsko-Włodawskie Lakeland. These are shallow eutrophic reservoirs of varied
water surface. What they have in common is the fact that they are linked by Wieprz-Krzna Canal.
The main aim of the present study was to determine the degree of faunistic similarity between
planktonic rorifer assemblages inhabiting these particular lakes. The authors were interested to
find out whether linking the lakes with the canal, as well as currently applied water exchange
could affect the degree of faunistic similarity occurring between these lakes. Physical and chemical analyses, as well as the studies of planktonic rotifers were carried out in the spring, summer
and autumn of 2012 and 2013. They included determining the qualitative composition and the
density of planktonic rotifers. The studies resulted in finding 50 species of Rotifera, with mean
density ranging from 75 to 855 ind. dm-3. The dominants included the common species of Keratella cochlearis, Keratella cochlearis tecta, Keratella quadrata, Polyarthra vulgaris, Kellicottia
longispina, Brachionus angularis, Ascomorpha odalis and Synchaeta pectinata. The results revealed high faunistic similarity among rotifer assemblages inhabiting a particular lake in different
years, and high diversification occurring between the lakes compared in the work. The analyses
showed that linking the lakes by Wieprz-Krzna Canal did not significantly affect the faunistic
similarity of these particular lakes.
Key words: Dratów lake, Krzczeń lake, Tomaszne lake, biological diversity, planktonic rotifers,
faunistic similarity
INTRODUCTION
A significant element of the water network of Polesie Lubelskie region is
the system of Wieprz-Krzna Canal which was built in the 60s of the 20th century
and comprises the area of nearly 530.000 ha. The canal was constructed in order
6
Andrzej Demetraki-Paleolog et al.
to intensify the agricultural produce due to amelioration or drainage of the arable
area. The system of the canal included some of the lakes. Surrounding them
completely or partially with a dike resulted in separating those lakes from the
catchment area and combining their waters, as well as the water of the rivers
[Wojciechowski 1991]. These changes intensified the proces of eutrophication
and led to transforming the structure of water biocenoses [Radwan and Kornijów
1994]. Such lakes included, among others, the reservoirs studied in the present
work, namely Dratów lake, Krzczeń lake and Tomaszne lake. Rotifers inhabiting
them provide good reserach material since they make the basic component of
minute zooplankton [Radwan 1973]. Feeding on bacteria, algae, protozoa and
dead organic matter, they play an important role in the trophodynamics of water
reservoirs and inhabit them relatively early [Hilbricht-Ilkowska 1964, Radwan
1973]. Some of them can also become good indicators of land ferility and water
purity [Karabin 1985, Paleolog et al. 1997, Radwan et al. 1988].
The studies of these lakes were undertaken in order to determine the degree of
faunistic similarity among rotifer assemblages inhabiting them and to assess, if possible, the effect of linking these lakes with Wieprz-Krzna Canal on such similarity.
STUDY AREA
The lakes of Dratów, Krzczeń and Tomaszne are situated in the area of
Łęczyńsko-Włodawskie Lakeland, eastern Poland. The morphometric features
characterizing these reservoirs are their insignificant depth and relatively large
area (Fig. 1). At the maximum level of buildup, the largest volume is that of
Dratów, while Krzczeń and Tomaszne are twice smaller.
The lakes mentioned here belong to shallow polymictic and eutrophic lakes
which are common in this area. They are used, at least periodically, for fishing
[Harasimiuk (ed.) 1998]. The structure of the catchment is dominated to a different
degree by meadows, pastures, arable area and forests. The physical and chemical
properties of the water in these lakes are presented in Table 1.
A significant element of water balance in the reservoirs is their supply from
the Canal which occurs every year mainly in autumn and winter when there is no
ice cap, and in early spring, immediately after the ice has melted [Solis 2012].
Water flows in through sluices directly from Wieprz-Krzna Canal. The lakes
receive from the canal some amount of water from the rivers. The most significant exchange of lake water with the water from the canal occurs apparently in
case of Dratów lake [Solis 2012]. Linking the studied lakes by means of a canal
also affects mutual mixing of the waters in those lakes. It is significant, regarding
the results of the present work, that the waters of Dratów lake and Tomaszne lake
are linked by a very long section of the canal, while the waters of Dratów and
Krzczeń lakes and those of Krzczeń and Tomaszne lakes are connected by signifi-
THE DEGREE OF SIMILARITY IN FAUNISTIC PLANKTONIC…
N
Depth
(Max.m.)
at the maximum level of damming
Dratów
168
4166
3,2
Krzczeń
174
2630
5,2
Tomaszne
95
2208
3,1
Poland
Tomaszne
Wi
ep
rzKrz
na
Lakes
al
Capacity
3 )
(thyous. m.....
C an
Area
(ha)
7
Krzczeń
Dratów
3km
Fig. 1. The map of the study area
Table 1. Physical and chemical parameters of the waters in the lakes: Dratów, Krzczeń, Tomaszne in
the 2012 year
Dratów
Lakes
Krzczeń
Temperature, oC
14.4 ±4.2
14.5 ±3.8
14.9 ±4.4
pH
8.53 ±0.33
8.42 ±0.42
8.51 ±0.22
305.83 ±48.8
271.1 ±50.2
350.6 ±4.8
Parameter of water
Conductivity, μS cm-2
-3
O2, mg dm
Tomaszne
10.56 ±2.4
10.56 ±2.8
11.51 ±3.1
N-NH4, mg dm-3
0.135 ±0.0315
0.106 ±0.0317
0.078 ±0.0177
N-NO3, mg dm-3
P-PO4, mg dm-3
0.122 ±0.0862
0.0575 ±0.038
0.126 ±0.0667
0.038 ±0.016
0.149 ±0.0733
0.029 ±0.024
Total P, mg dm-3
Chlorophyll, mg dm-3
0.137 ±0.074
65.39 ±40.78
0.229 ±0.077
146.44 ±68.73
0.077 ±0.049
46.83 ±24.05
cantly shorter sections of the canal. It is only in the recent twenty years that less
intense watner management, including introducing a lower amount of water into
the reservoirs, has been implemented [Chmielewski (ed.) 2006].
8
Andrzej Demetraki-Paleolog et al.
MATERIAL AND METHODS
The material for the studies was taken in the summer and autumn of 2012
and 2013 from three lakes of Łęczyńsko-Włodawskie Lakeland (eastern Poland),
namely Dratów, Krzczeń and Tomaszne lakes. In each study period, the plankton was sieved in three replications from the litoral zone and in three replications
from the pelagic zone, Since the study aimed at comparing the whole lakes, rather than their particular zones, the three replications from the litoral zone and
the three replications from the pelagial zone were treated as six replications of
the samples taken at a particular time from a particular lake. The samples were
collected by taking each time 10 dm3 of water with the use of „Toń II” sampler
at the depth of 0 to 1 m. Next, the water was sieved through a planktonic net no.
25 and condensed to the fixed volume of 100 cm3. The samples were preserved
in Lugol’s liquid and after a few hours they were put in formaldehyde with an
addition of glycerine. The samples preserved in this way were used to identify
the species and the number of rotifers, with the help of a reversed microscope.
The numer of individuals in the sample was calculated per 1 dm3 of water in the
reservoir.
The normal distribution of all the variables was verified with the help of
Shapiro-Wilk test. The significance of differences in rotifer density among the
individual lakes was checked using the ANOVA non-parametric rang test
(Kruskal-Wallis) in the SAS programme [SAS Institute Inc. 2001]. The similarity of rotifer assemblages in individual lakes and their zones was determined by
means of Sörensen index and cluster analysis with the use of Multi Variate Statistical Package – MVSP-3.1. The similarity analysis was performer by means
of the Unweighted Pair-Group Method Using Arithmetic Avarages – UPGMA.
Additionally, to determine the degree to which dominating species affect the
similarity between different rotifer assemblages the PCA (Principal Components
Analysis) was performed in the MVSP-3.1. programme. The calculations included
the index of domination, estimation of sustainability in the domination structure
[Bielańska-Grajner 2005] and the Shannon – Wiener index [Shannon and Wiener
1963]. Water for analyses and physical and chemical measurements was taken only
in 2012. This was done in the same periods, replications and lake zones, as in the
case of planktonic samples. Physical and chemical parameters were determined
according to Hermanowicz et al. [1976] and PN-ISO 10260 [2002].
RESULTS AND DISCUSSION
1. Qualitative structure
In the three studied lakes during three years the total numer of 50 planktonic
rotifer species was recorded. Their numer ranged in a very small area and in 2012
it amounted from 18 in Dratów lake to 20 in Krzczeń lake. In 2013 the numer was
THE DEGREE OF SIMILARITY IN FAUNISTIC PLANKTONIC…
Shannon index
9
number of species
Shannon index
Fig. 2. Number of species and Shannon index for planktonic rotifers in the lakes: Dratów,
Krzczeń, Tomaszne in the years 2012 and 2013
was slightly higher, since it ranged from 22 in Krzczeń lake to 24 in Tomaszne
lake (Fig. 2).
Species diversity of planktonic rotifers in the analyzed lakes was slightly
different, regerding species richness. The Shannon-Wiener index revealed its
highest values in Tomaszne lake, where it amounted to 0.81 in 2012, while in
2013 its value was at the level of 0.92. In Krzczeń lake it was 0.79 in 2012, yet
a year later species diversity was twice lower, 0.32. The lowest values of species
richness were noted in the biggest lake, Dratów, from 0.37 to 0.53 (Fig. 2).
According to the previous studies, this particular lake has been characterized by
low species diversity of planktonic rotifers since the time of its becoming a part
of the water system of Wieprz-Krzna Canal [Radwan 1973]. Such regularity has
been related by many researchers with improved fertility of the water in the lake,
following its connection with river waters [Bielańska-Grajner 1987, Radwan et
al. 1988, Paleolog et al. 1997, Imai Akio et al. 2001, Demetraki-Paleolog 2007].
In case of Dratów lake, river waters are delivered to it by menas of Wieprz-Krzna Canal at the amount higher than to the remaining lakes [Solis 2012].
No species that would be uncommon in the fauna of Poland were noted in
the studied lakes. However, some indicatory species were observed. The most
abundant group was eutrophobionts. There were 5 of them in Dratów lake and 3–4
in the remaining lakes. Indicatory species of oligotrophy were scarce. They were
found only in Krzczeń and Tomaszne lakes, at the amount of 1–2.
2. Quantitative structure
The highest rotifer density was recorded in the big, shallow, eutrophic lake
of Krzczeń and in the most abundant in water, also eutrophic lake of Dratów. In
Krzczeń the rotifer density ranged from 233 ind. dm-3 in 2012 roku to 854 ind. dm-3
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Andrzej Demetraki-Paleolog et al.
in 2013, while in Dratów it was from 494 ind. dm-3 in 2013 to 627 ind. dm-3 in 2012.
The much smaller lake of Tomaszne revealed the lowest rotifer density ranging
from 75 to 93 ind. dm-3 (Fig. 3). All the differences in rotifer density between
particular lakes were statistically significant. Similarly, the differences in rotifer
density between particular study years were statistically significant, except for
the difference between 2012 and 2013 in Tomaszne lake.
Fig. 3. Planktonic rotifer density (+SD) in the lakes: Dratów, Krzczeń, Tomaszne in the years
2012 and 2013
Fig. 4. Domination structure of planktonic rotifers (%) in the lakes: Dratów, Krzczeń, Tomaszne
in the years 2012 and 2013
The dominating species were common rotifers. The dominants included
Keratella cochlearis. Keratella quadrata and Brachionus angulasria in Dratów
lake, Keratella quadrata Keratella cochlearis, Keratella cochlearis tecta, Polyarthra vulgaris and Ascomorpha ovalis in Krzczeń lake, Kellicottia longispina,
Keratella cochlearis, Polyarthra vulgaris and Synchaeta pectinata in Tomaszne
lake (Fig 4). Rotifer assemblages were categorized according to Łuczak and
Wierzbowska [1981], Müller [1984], and Bielańska-Grajner [2005] into those
THE DEGREE OF SIMILARITY IN FAUNISTIC PLANKTONIC…
11
having sustainable or non-sustainable domination structure. According to the
authors, an assemblage is sustainable if it contains all the three domination classes
(dominants, sub-dominants and recendts), at least three of the species represent
dominants and none of them exceeds a 45% share of their total numer. Following
such a criterion, the domination structure of planktonic rotifers was sustainable
only in Krzczeń lake in 2012 and in Tomaszne lake in 2013. In the remaining
cases one of the criteria determining sustainability was not fulfilled, namely the
main dominant exceeded the 45% share in the total numer of rotifers (Fig. 4).
A sustainable domination structure may indicate a higher ecological status of the
reservoir and a relatively low trophy of its waters [Bielańska-Grajner 2005].
Despite frequently noted non-sustainable domination structure of planktonic
rotifers, inflowing river waters and the eutrophic character of these lakes [Radwan 1973, Pawlik-Skowrońska et al. 2014] the populations of Keratelli cochlearis
in these lakes did not reveal a high share of the tecta form. Such a high share of
the tecta is often considered as an important key indicator of high fertility of
water [Karabin and Ejsmont-Karabin 1996, Radwan et al. 2004].
3. Classification of rotifer assemblages
A cluster analysis of planktonic rotifer assemblages in the three lakes, performed on the basis of their quntitative composition suggests that planktonic
rotifer assemblages occurring in different periods in a particular lake are much
more similar to one another than planktonic rotifer assemblages inhabiting different lakes (Fig. 5). The highest degree of similarity was observed in rotifer
UPGMA
Krzczeń 2013 year
Krzczeń 2012 year
Tomaszne 2013 year
Tomaszne 2012 year
Dratów 2013 year
Dratów 2012 year
0.28
0.4
0.52
0.64
0.76
Sorensen's Coefficient
0.88
1
Fig. 5. Similarity structure of planktonic rotifer assemblages, based on their quantity composition
in the lakes: Dratów, Krzczeń, Tomaszne in the years 2012 and 2013
Andrzej Demetraki-Paleolog et al.
12
assemblages inhabiting Krzczeń lake in different years, with Sorensen’s coefficient of 0.78. In case of Dratów and Tomaszne lakes the values were 0.70 and
0.64, respectively. Significantly higher faunistic differences were observed between planktonic rotifer assemblages inhabiting different lakes. Sorensen’s coefficient for rotifer assemblages in Dratów and Krzczeń lakes was 0.44, whereas for
Tomaszne and Krzczeń lakes it was as low as 0.36. The analysis suggests that
linking the studied lakes by means of a canal did not have a significant effect on
the similarity regarding the species composition of planktonic rotifers in these
lakes. Such reasoning results from the fact that the lakes connected with the
longest section of the canal (Tomaszne and Dratów) are inhabited by rotifer
assemblages which are more similar to each other than those found in the lakes
linked by a much shorter fragment of the canal (Krzczeń and Dratów). Apparently, geological environment, the type of the nearest catchment area and some
other factors have a bigger effect on the species composition and domination
structure of rotifers than connecting the lakes with the canal. Numerous works
point at the dominating effect of the catchment area and the ground in shaping
the qualitative and quantitative structure of the plankton [Radwan 1973, Żurek
1982, Walsh et al. 2005, Van Egeren et al. 2011]. The faunistic similarities between rotifer assemblages inhabiting a particular lake at different periods (from
0.64 to 0.74), which are listed here, were not very significant when compared
with similarities observed in other lakes and ponds of Łęczyńsko-Włodawskie
Lakeland [Demetraki-Paleolog and Sender 2013, Demetraki-Paleolog 2013,
Demetraki-Paleolog at al. 2014, Demetraki-Paleolog and Kolejko 2014].
PCA case scores
0.9
Dratów 2013
Dratów 2012
0.7
0.5
A x is 2
0.4
0.2
-0.7 -0.5 -0.4 -0.2
-0.2
Krzczeń 2013
0.2
0.4
0.5
0.7
Tomaszne 2013
0.9
Tomaszne 2012
-0.4
-0.5
Krzczeń 2012
-0.7
Axis 1
Fig. 6. Principal Components Analysis of planktonic rotifers in the lakes: Dratów, Krzczeń, Tomaszne in the years 2012 and 2013
THE DEGREE OF SIMILARITY IN FAUNISTIC PLANKTONIC…
13
In order to eliminate the influence of some chance species on the picture of
faunistic similarities between the assemblages of planktonic rotifers, the Principle
Components Analysis, PCA, was performed, additionally. The analysis showed
that axis 1 accounts for the changing diversity of rotifer assemblages in 46.7%,
while axis 2 does this in 34.9%. Both axes therefore explain the variability to
a very high degree, namely 81.6%. The obtained results are very coherent with
the cluster analysis presented above (Fig. 5 and 6). It can be clearly noticed that
the highest similarity occurred between rotifer assemblages inhabiting the same
lake in different years. Rotifer assemblages inhabiting different eutrophic lakes,
even if the latter were linked by the canal, revealed significant differences. The
degree of faunistic diversification calculated on the basis of PCA is presented
graphically in Fig. 6. Similarity of rotifer assemblages on the graph seems to be
almost in conformity with the angles of a large equilateral triangle, which means
that faunistic diversification of these lakes was quite significant and it was similarly significant for all the lakes compared. In other words, lakes connected by
a short or a long section of the canal were faunistically diversified to a similar
degree. This confirms the fact that geological environment , type of the nearest
catchment and the type of its management, as well as other similar factors, have
a bigger effect on the species composition and domination structure of rotifers
than the fact of linking the lakes with the canal.
CONCLUSIONS
1. Fifty species of planktonic rotifers were found in the three lakes, including
5 species of indicatory autrophs and 2 indicatory species of oligotrophs.
2. Species richness was at a similar level in in all the three lakes, while
species diversity was much higher in Tomaszne lake, as compared with the
remaining ones.
3. The dominants included common common species of Keratella
cochlearis, Keratella cochlearis tecta, Keratella quadrata, Polyartchra vulgaris,
Kellicottia longispina, Brachionus angularis, Ascomorpha ovalis, Synchaeta
pectinata. Only in Krzczeń in 2012 and in Tomaszne in 2013 the domination
structure of rotifers was sustainable.
4. The character of rotifer assemblages suggests a high faunistic similarity
of the rotifers inhabiting a particular lake in different years, as well as a significant
faunistic diversification occurring between the lakes compared in the study.
5. The cluster analysis and PCA showed that linking the lakes by means of
Wieprz-Krzna canal and the scale of water exchange between these lakes does
not significantly affect faunistic similarity of these reservoirs.
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Andrzej Demetraki-Paleolog et al.
REFERENCES
Bielańska-Grajner I., 1987. Comparison of rotifer assemblages (Rotatoria) in different types of
water bodies of Upper Silesia (in Polish). Prz. Zool. 31, 37–47.
Bielańska-Grajner I., 2005. Psammon rotifers of water reservoirs of some areas of Poland (in
Polish). University of Silesia Publishing, 1–114.
Chmielewski T. (ed.)., 2006. Improvement of the ecological status and optimizing the recreational
use of catchment area of lakes Miejskie-Kleszczów, as a pilot implementation to introduce on
the post lakes areas of Euroregion Bug (in Polish). Publisher Ostrów Municipality – Earth Society of Ostrów Lubelski. Paragraph, 16–17.
Demetraki-Paleolog A., 2007. Planktonic rotifers (Rotifera) of rivers of west Lubelszczyzna (in
Polish). Wyd. AR, Lublin, 1–123.
Demetraki-Paleolog A., 2013. Changes in the sturucture of planktonic rotifers in some ponds of
the Poleski National Park during the years 1997 and 2009. Teka Kom. Ochr. Kszt. Środ. Przyr.
10, 53–61.
Demetraki-Paleolog A., Adamczuk M., Sender J., 2014. Multiannual changes in assemblages of
planktonic rotifers in ponds and of the Poleski National Park. Teka Kom. Ochr. Kszt. Środ.
Przyr. 11, 36–44.
Demetraki-Paleolog A., Kolejko M., 2014. Planktonic rotifers of three mesotrophic lakes of
Łęczyńsko-Włodawskie Lakeland (Eastern Poland). Teka Kom. Ochr. Kszt. Środ. Przyr. 11,
45–52.
Demetraki-Paleolog A., Sender J., 2013. Planktonic Rotifers of three eutrophic lakes of Łęczyńsko-Włodawskie Lakeland (Estern Poland). Teka Kom. Ochr. Kszt. Środ. Przyr. 10, 62–69.
Harasimiuk M., Michalczyk Z., Turczyńska M. (eds), 1998. Lakes of Łęczyńsko-Włodawskie
lakeland. Environmental monograph (in Polish). Biblioteka Monitoringu Środowiska, Lublin,
1–210.
Hermanowicz W., Dożańska W., Dojlido J., Koziorowski B., 1976. Physical-chemical studies of
water and wastes (in Polish). Arkady, Warszawa.
Hillbricht-Ilkowska A., 1964. The influence of the fish population on the biocenosis of the pond,
using rotifers fauna as an illustration. Ekol. Pol., ser. A. 12, 453–503.
Imai A., Fukushima T., Matsushige K., Kim Y.H., 2001. Fractionation and characterization of
dissolved organic matter in a shallow eutrophic lake, its inflowing rivers, and other organic
matter sources. Water Res. 35 (17), 4019–4028.
Karabin A., 1985. Pelagic zooplankton (Rotatoria + Crustacea) variation in the process of lake
eutrophication. I. Structural and quantitative features. Ekol. Pol. 33, 567–616.
Karabin A., Ejsmont-Karabin J., 1996. The structure, abundance and diversification of zooplankton in the lakes of the Krutynia river (Mazury Lakeland) (in Polish). Zesz. Nauk. Kom.Człow.
Środ. 13, 155–171.
Łuczak J., Wierzbowska T., 1981. Methods of analysis of zoocenosis (in Polish), in: M. Górny,
L. Grüm (eds), Methods used in soil zoology. PWN, Warszawa, 417–436.
Müller H.J., 1984. Ökologie. Gustav Fischer Verlag. Jena, 1–195.
Paleolog A., Radwan S., Kowalik W., Kowalczyk C., Stryjecki R., Zwolski W., 1997. Water
invertebrate fauna of Landscape Park „Lasy Janowskie” (in Polish), in: S. Radwan (ed.), Natural environment of Landscape Park „Lasy Janowskie”. Wyd. UMCS Lublin, 83–227, 1064-X,
117–133.
THE DEGREE OF SIMILARITY IN FAUNISTIC PLANKTONIC…
15
Pawlik-Skowrońska B., Toporowska M., Niedźwiecki M., 2014. Development of potentially
toxigenic cyanobacteria in a small, hydro-morphologically transformed lake included into the
Wieprz-Krzna canal system (eastern Poland). Teka Kom. Ochr. Kszt. Środ. Przyr. 11, 139–145.
PN-ISO 10260, 2002. Water quality. Measurement of biochemical parameters. Spectrophotometrical determination of chlorophyll a concentration (in Polish). PKN, Warszawa.
Radwan S., 1973. Pelagic rotifers of Łęczyńsko-Wodawskie Lakeland. Faunistic and ecological
study (in Polish). Shortcut of habilitation dissertation. Rozprawy Naukowe AR w Lublinie 8,
1–57.
Radwan S., Bielańska-Grajner I., Ejsmont-Karabin J., 2004. Main part. Monogononta – Systematic
part. 32.A, in: S. Radwan (ed.), Rotifers. Freshwater fauna of Poland. Tercja, Łódź, 1–146.
Radwan S., Jarzynowa B., Zwolski W., Girsztowtt K., Kowalczyk C., Kowalik W., Paleolog A.,
1988. Ecological characteristic of upper and middle course of Bystrzyca Lubelska River its
tributaries and Zemborzyckie Lake (in Polish). Rocz. Nauk. PZW 1, Warszawa, 123–156.
Radwan S., Kornijów R. 1994. Hydrobiological and hydrochemical profile of surface water (in
Polish), in: Natural environment in the impact zone of Wieprz-Krzna Canal. AR w Lublinie,
47–58.
SAS Institute Inc. 2001. SAS User’s Guide. Version 8.2 Edition, SAS Institute Inc., Cary.
Shannon C.E., Wiener W., 1963. The mathematical theory of communication. University of Illinois
Press Urban, 1–117.
Solis M., 2012. Wpływ kanału Wieprz-Krzna na właściwości fizyczno-chemiczne i biologiczne
wód w wybranych zbiornikach retencyjnych. Inż. Ekol. 29, 182–191.
Walsh S.E., Soranno P.A., Rutledge D.T., 2003. Lakes, wetlands, and streams as predictors of
land use/cover distribution. Environ. Manag. 31 (2), 0198–0214.
Wojciechowski K.H., 1991. The connection between lake water and surface and underground
water (in Polish), in: Łęczyńsko-Włodawskie Lakes, Stud. Ośr. Dok. Fizjogr. 19, 95–101.
Van Egeren S.J., Dodson S.I., Torke B., Maxted J.T., 2011. The relative significance of environmental and anthropogenic factors affecting zooplankton community structure in Southeast
Wisconsin Till Plain lakes. Hydrobiologia 668 (1), 137–146.
Żurek R., 1982. Effect of suspended materials on zooplankton. 2. Laboratory investigations of
Daphnia hyalina Leydig. Acta Hydrobiol. 24, 187–288.
STOPIEŃ PODOBIEŃSTWA FAUNISTYCZNEGO ZGRUPOWAŃ WROTKÓW
PLANKTONOWYCH W TRZECH JEZIORACH POŁĄCZONYCH
KANAŁEM WIEPRZ-KRZNA (WSCHODNIA POLSKA)
Streszczenie. Dratów, Krzczeń i Tomaszne należą do bardzo cennych przyrodniczo jezior Polski
i Pojezierza Łęczyńsko-Włodawskiego. Są one płytkimi zbiornikami eutroficznymi o różnej powierzchni lustra wody. Ich cechą wspólną jest połączenie kanałem Wieprz-Krzna. Głównym
celem badań było określenie stopnia podobieństwa faunistycznego wrotków planktonowych zasiedlających te jeziora. Autorów ciekawiło, czy połączenie kanałem i aktualnie stosowana wymiana wody może mieć wpływ na stopień podobieństwa faunistycznego występujący między tymi
jeziorami. Badania fizyko-chemiczne i badania wrotków planktonowych prowadzono wiosną,
latem i jesienią 2012 i 2013 roku. Przeprowadzono w nich badania nad składem jakościowym
i zagęszczeniem wrotków planktonowych. Badania te pozwoliły na stwierdzenie 50 gatunków
Rotifera o zagęszczeniu wahającym się w szerokim zakresie od 75 do 855 ind. dm-3. Wśród dominantów znalazły się pospolite gatunki: Keratella cochlearis, Keratella cochlearis tecta, Keratella
16
Andrzej Demetraki-Paleolog et al.
quadrata, Polyarthra vulgaris, Kellicottia longispina, Brachionus angularis, Ascomorpha odalis
i Synchaeta pectinata. Badania wykazały duże podobieństwo faunistyczne zgrupowań wrotków
zasiedlających dane jezioro w różnych latach i znaczne zróżnicowanie występujące pomiędzy
porównywanymi jeziorami. Przeprowadzone analizy wykazały, że połączenie jezior kanałem
Wieprz-Krzna nie wpływa w znaczący sposób na upodobnienie się faunistyczne tych zbiorników
do siebie.
Słowa kluczowe: jezioro Dratów, jezioro Krzczeń, jezioro Tomaszne, różnorodność biologiczna,
wrotki planktonowe, podobieństwo faunistyczne